


Double Your Pleasure, Double Your Fun

by bitter_crimson (Krim)



Category: Merlin (TV)
Genre: Animal Transformation, Crack, M/M, snake sex
Language: English
Status: Completed
Published: 2009-09-01
Updated: 2009-09-01
Packaged: 2019-10-09 08:43:31
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,402
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17403725
Author URL: https://archiveofourown.org/users/Krim/pseuds/bitter_crimson
Summary: Merlin and Arthur turn into snakes and have snake sex





	Double Your Pleasure, Double Your Fun

**Author's Note:**

> Written for kink_bingo for the prompt "double penetration (two holes)." I may have played a little fast and loose with snake reproductive biology, but the basics are (mostly) accurate. Male snakes have two phallic sex organs, called hemipenes, which are usually held inverted inside the body. In the inverted state, they appear from the outside to be identical to a female snake's cloaca (but the cavities are not as deep). This is all you really need to know!

It's just another ordinary day in Camelot.

Which, of course, means that Merlin and Arthur are being held captive by some crazy peasants in the middle of the woods.

Said crazy peasants, currently about fifteen feet in front of Merlin and upside-down, are glaring furiously and shouting at him. He's having a bit of trouble understanding what they're saying, due to the dizziness. _Huh,_ he thinks. _Why am I dizzy? Have I been hit on the head?_ Merlin tries to reach a hand up to feel at his scalp, only to discover that his arms are already stretched above his head. 

Merlin frowns and is about to start puzzling this out when his body abruptly twists and rotates sideways and he sees Arthur next to him, hair sticking straight up and with an extremely angry expression on his flushed face.

"Merlin, you _idiot_ ," Arthur is shouting, trying to swing his arms toward Merlin. "Snap out of it!"

_Swinging_ , Merlin thinks, and then the vertigo hits and he realizes even before craning his neck to stare up at his feet that he and Arthur are suspended upside down. When he does look, he sees the rope tightly binding his own feet together, attached to a tree high above. Then he looks down at the dirt pit filled with a multitude of snakes.

_Oh, right,_ Merlin thinks, _because all the previous ways people have tried to kill us just weren't ridiculous enough._

His head has cleared enough now that Merlin can make out some of what the peasant couple are shouting at them: something about murderers and evil and meaning no harm and taking children away. Next to him Arthur is also shouting, and Merlin tries to tune the couple out, concentrating on Arthur's voice.

"--yourself! We need to focus so we can get down from here." Merlin's body has spun around again so his back is to Arthur and he tries to pinwheel his arms through the air to turn himself back. "Are you even listening to me?" Arthur continues. "Merlin--"

"What happened?" Merlin asks, when he can see Arthur's face out of the corner of his eye. Merlin's dizzy and nauseous and his head feels like it's pounding, but none of that explains how they got up here in the first place. The last he remembers, he and Arthur had been on the road back to the castle and had happened upon a cottage. The old couple who lived there -- the couple currently hurling death threats at them from a few yards away -- had demanded they stop in and rest a bit. They had even offered them soup...

"Food," Merlin says. "There was something in the food."

"Very well done, Merlin." Arthur glares at him. "Yes, they poisoned us and then while we were unconscious, they tied us up in this tree."

Merlin frowns and tries to think clearly. "Why didn't they just kill us with the poison?"

"You know, maybe next time they'll do just that! I've given up trying to work out why people keep trying to kill me in newer and more interesting ways all the time. Right now I just want to be _down from here_."

Blinking, Merlin thinks, _But there are snakes down there. Some of them could be deadly._ And then looking down below him: _Wait, why don't the snakes attack each other?_

Suddenly Merlin is falling, and he yells and throws his arms out in front of himself, except they're not there. He panics, but before he can figure out what has happened to his arms he thinks, _Snakes,_ and pushes down with his magic, holding the snakes still and trying to halt his fall. He pushes as hard as he can, but his head is still throbbing and it's not quite enough, though he's managed to slow his descent, and he can stop the snakes from striking at him when he lands. As Merlin falls upon the snakes, he uses as much of his magic as he can to hold them in place and then turns his head to look back up to see if Arthur is safe, if he's still hanging from the tree.

Arthur is nowhere to be seen. Something's funny about Merlin's vision, too, a little fuzzy, and the field of view is all wrong. His tongue darts out to wet his lips as he tries to figure out what's wrong, what happened to Arthur, and most importantly, what's going on.

Merlin pulls his tongue back into his mouth and thinks, _Hey, that smells like Arthur!_ Then he realizes he somehow just used his tongue to smell.

Slowly, Merlin turns his head to the side, and oh, the fog is definitely clearing now. Merlin sees that the reason he could not throw his arms in front of himself was because he had none, because he is a snake.

"Merlin, you idiot!" comes a furious voice from behind him, and Merlin whips his head around just in time to see one of the snakes strike. He recoils and is startled at just how fast he can move, darting out of reach and pulling his body taut into its own striking position.

_Wait,_ he thinks, looking at the golden-colored serpent, and freezes. "Arthur?"

\---

It is indeed Arthur.

"This isn't happening," Merlin says to himself. Or rather doesn't say, because as snakes it's not like he and Arthur can actually speak. Yet somehow they can still hear each other as if they are speaking; Merlin suspects it's some kind of telepathy. It feels similar to the way he could hear the Dragon, or the Druid boy. He can't hear all of Arthur's thoughts, only the ones Arthur intentionally broadcasts at him.

Such as: "Stop! Merlin! I demand an explanation for this."

Merlin stops slithering along the forest floor and turns his head around to see Arthur coiled up on top of a small patch of weeds at the foot of a tree, glaring at him. At least, it looks like glaring. Arthur's snake eyes aren't really all that expressive.

"Um," Merlin says, flicking his tongue out nervously. "Explanation for what?"

"Why we're _snakes_!" shouts Arthur, his muscles twitching in irritation.

"Er, why would I know?" Merlin swings his head from side to side, looking for somewhere to hide should Arthur try to attack him.

Arthur hisses lowly. "Merlin, I'm not an _idiot_. You think I really haven't figured it out, after all this time?"

Merlin thinks about it. He considers the possibility that maybe Arthur is referring to something other than his magic. There's still plausible excuses he can make: the old couple could have been using magic! Maybe stringing Arthur and him up above the snakes was all part of some snake transformation ritual.

Only Arthur is staring at him steadily and somehow Merlin knows it's nothing else; Arthur knows, and has known, apparently, without Merlin even telling him. Merlin feels something unpleasant building in his gut and suspects it is either hunger or guilt. He wants to explain, to tell Arthur why he hadn't said anything earlier, to assure him it doesn't mean Merlin didn't trust him, but instead Merlin says: "Oh."

There's a pause, Arthur still gazing at him unblinkingly (though, as he no longer has eyelids, this may not have any significance). Merlin continues to think of dozens of things he could say but none of them seem to be projecting. Finally, Arthur expels air in a kind of wheeze that Merlin realizes must be a sigh, and says, "So, we've escaped. You can turn us back, now."

"Um, right." Merlin focuses on his magic and it's still there, thankfully; turning into a snake hasn't changed that. He looks at Arthur, sleek shiny body obscured by the weeds, and tries to picture him as a human, pushing magic at him.

"I said you could turn us back," repeats Arthur.

"I'm trying!" Merlin shoots back, turning his magic on himself, thinking, _Legs, arms, human human human._

"You could try a little faster," Arthur suggests.

"You know, this isn't as easy as you seem to think it is!"

"Well, how did you turn us into snakes in the first place?"

"I don't know! I didn't do anything, it just..." Merlin slithers over to Arthur's tree and Arthur's raised head turns to follow his approach. "Maybe we need to be next to each other, like we were before."

"Do we need to be strung up again, too? I think that might be a little difficult to manage given our current shapes."

"Shut up!" Merlin snaps, and without meaning to he snaps his jaws at the same time, barely an inch away from Arthur's neck. Arthur starts and jerks away, drawing his body tight and hissing. "Sorry, sorry!" says Merlin hurriedly. "I didn't mean... It was just an instinct."

"Well, keep your instincts under control, then!" Arthur says, still hissing. "I have no desire to bleed to death in the woods as a _serpent_."

"You wouldn't have _died_ ," says Merlin, because _honestly_ , it's not like his fangs are _that_ long. He thinks, and then his mind seizes on the first thing Arthur said. "Wait, I remember something."

"How to turn us back into people?"

"Maybe," Merlin says. "We have to get back to the castle."

"What?" asks Arthur, incredulous. He has finally stopped hissing, though. "I don't know if you've noticed, but we're _snakes_. Even if we managed to get all the way back to Camelot from here, two snakes slithering around the castle would not go unnoticed."

"I know." Merlin moves to approach Arthur again, but the prince jerks back, holding himself very still. "Look, I promise I won't try to bite you this time," Merlin says. "Just trust me."

Arthur looks at him with those dark eyes, pauses, and raises his neck up into the air. "Please, _Merlin_. As if you could even bite me if you tried."

Merlin wishes he were human right now so he could roll his eyes, but he contents himself with doing so in his mind. "Okay, I _think_ this should work," he says, crawling over Arthur's middle, then circling around to burrow under him and come up on the other side.

"Erm," says Arthur. They're very close, and as Merlin continues to twine his body with Arthur's, he thinks he feels the prince's heart speed up. "What _exactly_ are you doing?"

"Trust me," Merlin repeats, pressing his head on top of Arthur's. Then he focuses all his magic and thinks, _Camelot_.

\---

"Augh! Eurgh!" Arthur groans, snake body twitching on Merlin's bed. "What--! What did you just--!"

Merlin tries to relocate his center of balance, pulling himself upright while the room swims around him. "Sorry," he says, "it's the first time I've tried that one."

"First..." Arthur, still twitching, raises his head weakly and flicks his tongue out and back in. "We're in your room!"

"Yeah," says Merlin, world still spinning. "It was... teleportation, or something like it."

Arthur stares. "You can do that?"

"Apparently. I think it helped that our bodies were smaller than usual, but I still don't think I'll be able to do any more magic for a little while." 

"Oh," Arthur says. "So we're supposed to just be snakes sitting about in your room until then, is that it?"

" _No_ ," says Merlin. "We have to... Under my bed."

It's not really a coherent sentence, but Arthur slithers off the side of Merlin's mattress just the same. Merlin watches him go, world spinning slightly less now.

"Under your bed, what?" calls Arthur. "There's nothing interesting down here. A large dusty book..."

"The book, yes, get the book." Merlin waits, and by the time he sees Arthur emerging from the bed, his tail coiled around and dragging the heavy tome, the room is completely still.

"All right, so it's a book," Arthur says, dropping it on the stone. "What good does that do us?"

Merlin slithers off the bed and joins Arthur in front of the book. "It's a _magic_ book. It should have the spell I accidentally used to turn us into snakes." He tries to picture the page that spell had been on, and the book's cover flies open, pages turning rapidly.

"Only you, Merlin, would change us into snakes by _mistake_."

Merlin is about to respond, but the book has opened to the correct page, so he studies it instead. He hadn't really read this page that intently; he'd flipped past it when looking for a spell to make the snakes on Knight Valiant's shield come to life, but he'd obviously been looking for something to animate inanimate animals, not to turn people into beasts. Apparently, though, it had stuck in some corner of his mind, associated with snakes.

"Well? Is that it?" Arthur nudges Merlin's flank with his own, making Merlin's muscles twitch.

"Shhh! I'm trying to read, here." The end of Merlin's tail flicks irritably.

\---

The book, however, is not very forthcoming.

"That's all it says!" Merlin insists.

"What, that we'll change back as soon as we feel _comfortable_? I think this book of yours is kind of rubbish."

" _You're_ rubbish," Merlin says, then winces. Before Arthur can respond he continues, "Anyway, the book says we have to feel comfortable _living_ as the animal."

"What in the world does that mean?" complains Arthur. "Also, I'm hungry. What are we supposed to eat?" Merlin's stomach is starting to hurt again and he is curious about this as well.

Right on a cue, a pair of mice run out of a hole in the wall and patter along the floorboards.

"You have _got_ to be joking," Arthur says.

\---

Fortunately, rodent seems to taste a lot better when you're a snake.

"I can't believe I just ate that," Arthur says.

Merlin stretches his jaw as wide open as he can and listens to it pop and crack. "I don't know," he says. "It tasted kind of like chicken." He tilts his neck to one side. "Hey, how long do you think we can stay snakes before someone in the castle notices we're missing?"

Arthur pauses and holds his body in a tight coil, nothing moving except his flicking tongue. "Well, we were away from the castle, and something could easily have delayed us several days in returning, but if we're gone longer than that..."

"So we have a few days to get as comfortable as we can being snakes," Merlin concludes. "That can't be that hard."

\---

It turns out to be slightly harder than he thought.

For the first part, it turns out people in Camelot don't really _like_ snakes very much, and that Merlin and Arthur can only communicate with each other, not anyone else. This leads to the fun experience of Gaius throwing several books, a shoe, and a kettle at them before they manage to escape through a hole in the wall. Then when they exit out into a castle corridor they're almost trampled by a guard and two servants.

"This is outrageous!" exclaims Arthur, darting in and out amongst the descending boots. "Don't they know who I am?"

"Maybe you should bite them, sire," Merlin suggests in a chipper tone. He's managed to escape the shoes and is hiding along the wall. "I'm sure they'd all realize their mistake and bow down before you if you did that."

Arthur hisses but is too involved in escaping to make a retort. Finally he gets clear of the feet and the two of them take off down the halls.

The second unexpected hardship is that snakes don't really do much.

"I'm so full," Merlin moans when they finally arrive in Arthur's rooms, having decided they'll be safest there, since no one is likely to enter them while Arthur is away. "I want to sleep for a week."

"We can't sleep for a week," says Arthur snappily. "We've got to do other snakish things."

Merlin yawns, popping his jaw again, and ignores Arthur. That patch of sunlight on the stone by the window looks particularly good, so he slithers over to it and curls up in a loose coil.

"Merlin, are you listening to me?" asks Arthur, his tongue flicking against Merlin's back.

Sighing, Merlin replies, "We're supposed to be doing whatever makes us comfortable as snakes. And after that mouse, I feel like sleeping. Don't you?"

"No," says Arthur petulantly, but he pokes his head into the sunlight and sighs contently when it hits his scales.

Merlin lets out a small annoyed hiss when Arthur starts draping himself on top of Merlin's body, and then there's a brief lazy struggle where they each try to get as much of their bodies in the light as possible. They end up in a big pile of coils, warming in the sunlight, and subsequently warming each other.

"Maybe just... a short... nap..." says Arthur as he drifts off to sleep.

\---

Several days later, they finally move when they both have to go to the bathroom.

"That's disgusting," Arthur says, staring at the pile of waste matter.

"Why is some of it brown and some of it white?" Merlin asks, inspecting the white chalky substance with fascination, but careful not to flick his tongue too close to it.

"I have no clue," says Arthur. He fidgets, his flank twitching against Merlin. "Um," he says.

Merlin turns his neck and looks at Arthur. "What?" he asks.

"Did you notice, by any chance, that we seem to have two penises?"

Merlin has actually noticed that. He also noticed that their penises appear to invert inside their bodies when they're not in use.

"That doesn't seem right," Arthur comments on the inverted penises, but Merlin kind of disagrees. In fact...

"We've eaten, slept, and shit," says Merlin, staring at Arthur and flicking his tongue in and out rapidly, tasting the air between them. "What else do animals do?"

"What?" Arthur asks confusedly.

\---

Thankfully, Arthur doesn't take that much convincing once Merlin explains his idea. Merlin's a little relieved, and some of the weight in his stomach, that was there since Arthur said he knew about Merlin's magic, lifts. He won't ever say anything to Arthur about it, about how afraid he was that Arthur might not trust him anymore, might end this part of their relationship even if he wasn't going to turn Merlin in, but it's there.

"Really, Merlin," Arthur says. "Get on with it."

They're lying entwined in the sun again, their tails pressed together, and Merlin has managed to figure out how to keep his two penises out and erect without going to the bathroom. "Do you think this will really work? I don't know if male snakes usually have sex with other male snakes in the wild."

"Performance anxiety?" Arthur asks, a smirk evident in his voice despite his expressionless snake face.

Really, the only appropriate response to that is to thrust both his erect penises into Arthur's inverted ones, so Merlin does so. Arthur grunts and his body tenses up, and Merlin holds still for a moment once he's as far inside as he can go. His penises won't go all the way in, and the tips are rubbing up against the inverted tips of Arthur's penises. It feels strange: not the same as the sex they usually have as humans, but still, there's something pleasurable in the sensation.

"Merlin," Arthur hisses out. " _Move._ "

Merlin does, coiling his body more tightly around Arthur's as he pumps his tail, drawing his penises in and out of Arthur's two holes, and both of them begin breathing loudly through open mouths. Merlin's body tenses and his muscles grip against Arthur's scales, and a moment later, Merlin shoots into Arthur's inverted penises.

Then Merlin blinks his eyes at the now-human Arthur lying underneath him, his cock still inside Arthur's ass.

" _Finally,_ " growls Arthur, pushing Merlin off, then flipping around and pulling him back down into a kiss.

\---

"So," Merlin says when they are lying spent on Arthur's bed, poking Arthur in the shoulder. "In the end, my penises saved the day."

Arthur narrows his eyes and grabs Merlin's finger. "I think you'll find it was your magic that turned us into snakes in the first place."

"You're completely right, your highness. My magic _and_ my penises saved the day."

Arthur groans and rolls over. "How lucky you only have one penis most of the time."

Merlin grins. "So," he says, "how do you feel about bird sex?"


End file.
